US team finds potential path for hepatitis C drugs

WASHINGTON (Reuters) - U.S. scientists have identified a new class of drugs that appear to block the hepatitis C virus from replicating in laboratory experiments, researchers said on Wednesday.

The team discovered activity within a key protein of the hepatitis C virus (HCV) essential for the virus to reproduce, they reported in the online journal Science Translational Medicine.

The researchers also identified small molecules capable of inhibiting replication of the virus, senior author Dr. Jeffrey Glenn of Stanford University said in a telephone interview.

Glenn and colleagues then set out to look for compounds that could prevent the protein from working.

"The compounds we discovered represent a new class of potential drugs that appear to specifically attack the virus's ability to set up shop in the liver cells," said Glenn, director of Stanford's Center for Hepatitis and Liver Tissue Engineering,.

"Hepatitis C creates a novice structure in the infected cell where it replicates and it looks like this class of compounds interferes with the virus's ability to establish that structure," he said.

Glenn said he expects derivatives of the compounds to go into human trials within 18 months, after additional preclinical and animal testing.

Glenn and several members of his team have an equity interest in Eiger BioPharmaceuticals, a privately held start-up based in Palo Alto, California that is seeking to develop this new class of drugs. Stanford University has filed patents for the compounds, which have been licensed to Eiger.

Hepatitis C infects more than 150 million people worldwide and is the leading cause of chronic liver cancer and liver transplants in the United States.

Glenn said the current therapy for Hepatitis C, combinations of interferon and ribavirin, is only somewhat effective and often toxic.

Glenn said the first goal is to add new drugs to that combination. The next step would be to have enough new drugs in a mix to effectively fight the virus.

"We need a cocktail of multiple drugs because this virus has a very high rate of developing resistance," Glenn said. "We really need to hit it from multiple angles at the same time to decrease the chances that any mutation that occurs in the virus could overcome all the drugs at the same time."